Cameras with increasingly more pixels are integrated into mobile phones, and in daily life, people increasingly use mobile phones instead of dedicated cameras to shoot photos. However, a mobile phone stays at a lock screen in most cases. To shoot a photo or video when seeing a novel or special scene or a wonderful moment, a mobile phone user needs to complete the following steps: 1) press a power button to lighten the screen, 2) unlock the screen, 3) start a camera application, 4) switch to a photo or video shooting program, 5) find a shooting range, and 6) press a shooting button. However, a wonderful view is instantaneous and usually has gone by the time the mobile phone user accesses the photo or video shooting program.